Air by Propeller's API forecast response with Decodable and CodingKeys

PropellerForecastResponse.swift

struct PropellerForecastResponse: Decodable {
    let properties: PropellerForecastProperties
}

struct PropellerForecastProperties: Decodable {
    let risk: String // risk of adverse respiratory conditions: "high", "medium" or "low"
    let probability: Double // probability of adverse respiratory conditions: ex. 0.4938...
}

// MARK: - CodingKeys

extension PropellerForecastProperties {
    enum CodingKeys: String, CodingKey {
        case risk = "code"
        case probability = "value"
    }
}